Rosa Luxemburg

Social Reform or Revolution (1900)
“…people who pronounce themselves in favour of the method of legislative reform in place of & in contradistinction to the conquest of political power & social revolution, do not really choose a more tranquil, calmer & slower road to the same goal, but a different goal.”
“…the conquest of a parliamentary reformist majority is a calculation which, entirely in the spirit of bourgeois liberalism, preoccupies itself with one side – the formal side – of democracy, but does not take into account the other side, its real content. All in all, parliamentarianism is not a directly socialist element impregnating gradually the whole capitalist society. It is, on the contrary, a specific form of the bourgeois class state, helping to ripen & develop the existing class antagonisms of capitalism.”
“It is not true that socialism will arise automatically from the daily struggle of the working class. Socialism will be a consequence of:
1. The growing contradictions of the capitalist economy, &
2. The comprehension of the working class of the unavoidability of the suppression of these contradictions through a social transformation.
When, in the manner of revisionism, the first condition is denied & the second rejected, the labour movement finds itself reduced to a simple co-operative & reformist movement. We move here in a straight line toward the total abandonment of the class viewpoint.”

Accumulation of Capital (1913)

“Historically, the errors committed by a truly revolutionary movement are infinitely more fruitful than the infallibility of the cleverest Central Committee.”

The Crisis in German Social Democracy (The Junius Pamphlet), 1915
“The proletariat is dependent in its actions upon the degree of maturity to which social evolution has advanced. But again, social evolution is not a thing apart from the proletariat; it is in the same measure its driving force & its cause as well as its product & effect. And although we can no more skip a period in our historical development than a man can jump over his own shadow, it lies within our power to accelerate or retard it.”